html, body { margin: 0; height: 100%; background: #fff; }
iframe { position: fixed; inset: 0; width: 100%; height: 100%; border: 0; }
p { margin: 0; padding: 2rem 1.25rem; font: 1rem/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; color: #222; text-align: center; }